The present invention relates to the field of perfumery. It concerns more particularly the use as a perfuming ingredient of a compound of formula 
wherein either the dotted line indicates the location of a double bond, n is equal to 1 and R represents a hydrogen atom or a methyl radical, or the dotted line indicates the location of a single bond, n is equal to 0 and R represents a hydrogen atom.
The cyclic compounds of formula (I) possess very useful and appreciated odor properties. Therefore, they can be useful for the preparation of perfumes, perfuming compositions and perfumed products. They are employed in order to confer odor notes of the lily of the valley type.
The structure of the compound of formula (I) wherein the dotted line indicates the location of a single bond, n is equal to 0 and R represents a hydrogen atom, namely (4-tert-butyl-1-cyclohexyl)acetaldehyde, is known. In fact, this compound is cited by G. Ohloff et al. as a synthesis intermediate in Helvetica Chimica Acta (1983), 66(5), 1343-1354. However, said reference does not contain any description of the odor of (4-tert-butyl-1-cyclohexyl)acetaldehyde. The organoleptic properties of some compounds synthesized are described in this document, but the described odors are typical of those of compounds of the steroid type, while the compound of the invention possesses a very natural odor, which is reminiscent of that of Lilial(copyright) [3-(4-tert-butylphenyl)-2-methylpropanal), and which presents, besides, a nice citrus connotation. Moreover, (4-tert-butyl-1-cyclohexyl) acetaldehyde possesses in its bottom note, a very original and appreciated odor of the melon, aqueous, mandarin-fresh type.
The compounds of formula (I), wherein the dotted line indicates the location of a double bond, n is equal to 1 and R represents a hydrogen atom or a methyl radical, namely 3-(4-tert-butyl-1-cyclohexen-1-yl)propanal and 3-(4-tert-butyl-1-cyclohexen-1-yl)2-methylpropanal are novel compounds. The known compounds having the closest structure to those two, are respectively Bourgeonal(copyright) [3-(4-tert-butylphenyl)propanal] and Lilial(copyright) [3-(4-tert-butylphenyl)-2-methylpropanal]. Besides, European patent application EP 685 444 discloses the odor properties of some aldehydes, the structure of which is also close to that of the compounds of the invention. However, contrary to the compounds of the invention, these known aldehydes possess an aromatic ring. Despite the large number of known aldehydes having a structure which is close to that of the compounds of formula (I), nothing in the literature suggests that the compounds of formula (I) according to the invention would be susceptible of being interesting from an olfactory point of view.
Surprisingly, we have now been able to establish that the compounds of formula (I) possess very interesting odor properties, providing useful nuances to the perfumer""s palette. These compounds possess an odor which is reminiscent of that of Lilial(copyright) and Bourgeonal(copyright), but which is also fresher, more floral and less fatty than that of the known products.
The invention is thus related to a method to confer, improve, enhance or modify the odor properties of a perfuming composition or a perfumed product, which method comprises adding a compound of formula 
wherein either the dotted line indicates the location of a double bond, n is equal to 1 and R represents a hydrogen atom or a methyl radical, or the dotted line indicates the location of a single bond, n is equal to 0 and R represents a hydrogen atom, as a perfuming ingredient to said composition or product.
The compounds of the invention thus make it possible to confer, improve, enhance or modify the odor of consumer products, as well as of perfuming bases or concentrates. In other words, they can impart to the latter their characteristic odor, as the case may be modifying and/or improving the original odor properties of the products and compositions in which they are incorporated. These products thus become more appealing to the consumer and have an enhanced odor impact.
In particular, 3-(4-tert-butyl-1-cyclohexen-1-yl)-2-methylpropanal presents an odor with a top note of the lily of the valley, almost white flower, freesia type. Its odor is mild and very pleasant.
3-(4-Tert-butyl-1-cyclohexen-1-yl)propanal is a preferred compound according to the invention. The latter presents an odor of the aldehydic, flowery-lily of the valley, fatty type with a Lilial(copyright)/Bourgeonal(copyright) connotation, but its odor is definitely more floral, more white flower than that of Lilial(copyright). It is also more powerful than the latter, more substantive on the linen, which property presents a distinct advantage for the perfuming of products such as detergents and fabric softeners. Moreover, the odor of this preferred compound of the invention has a surprising slight anisic tone, providing thus a novel odor nuance to the perfumer""s palette.
The compounds of the invention can suit an utilization in fine perfumery, in perfumes, colognes, or after-shave lotions, as well as any current use in perfumery such as the perfuming of soaps, shower or bath gels, hygiene products, hair-care products such as shampoos, as well as body deodorants and air fresheners, or yet cosmetic preparations.
The compounds (I) can also be used in applications such as liquid or solid detergents for textile treatment, fabric softeners, or yet detergent compositions or cleaning products for dishes or varied surfaces, for a domestic as well as an industrial use.
In these applications, the compounds of the invention can be used alone as well as mixed with other perfuming ingredients, solvents or additives commonly used in perfumery. The nature and variety of these co-ingredients does not require a more detailed description here, which would not be exhaustive anyway. In fact, a person skilled in the art having a general knowledge, is able to choose them according to the nature of the product that has to be perfumed and the olfactory effect sought.
These perfuming co-ingredients belong to varied chemical groups such as alcohols, aldehydes, ketones, esters, ethers, acetates, nitrites, terpenic hydrocarbons, herterocyclic nitrogen- or sulfur-containing compounds, as well as essential oils of natural or synthetic origin. Many of these ingredients are listed in reference texts such as S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, N.J., USA or more recent versions thereof, or in other similar books.
The proportions in which the compounds according to the invention can be incorporated in the different products mentioned above, vary in a large range of values. These values depend on the nature of the article or product that has to be perfumed, and on the olfactory effect sought, as well as on the nature of the co-ingredients in a given composition when the compounds of the invention are used in admixture with perfuming co-ingredients, solvents or additives of current use in the art.
For instance, typical concentrations from about 4 to 10% by weight, or even 20% or more by weight of the compound (I) of the invention, with respect to the weight of the composition in which it is incorporated can be used. Much lower concentrations than these can be used when these compounds are directly applied for perfuming the consumer products mentioned above.
The compounds of formula (I) wherein the dotted line indicates the location of a double bond, n is equal to 1 and R represents a hydrogen atom or a methyl radical can be prepared by a three, respectively five-step process, starting form 4-tert-butyl-cyclohexanone. The latter, in the presence of the classical reactant 2-(2-bromoethyl)-1,3-dioxalane, makes it possible to obtain, after a Grignard reaction followed by a dehydration reaction and a hydrolysis, in standard reaction conditions, 3-(4-tert-butyl-1-cyclohexen-1-yl)propanal. The intermediates of this synthesis, namely 4-tert-butyl-1-[2-(1,3-dioxalan-2-yl)ethyl]-1-cyclohexanol at the end of the first step, and a mixture of 2-[2-(4-tert-butyl-1-cyclohexen-1-yl)ethyl]-1,3-dioxalane and 2-[2-(4-tert-1-butyl-1-cyclohexylidene)ethyl] at the end of the second step, are novel compounds. The final product of the synthesis, namely 3-(4-tert-butyl-1-cyclohexen-1-yl)propanal, after a reaction of the Mannich type, followed by a selective hydrogenation, leads to 3-(4-tert-butyl-1-cyclohexen-1-yl)-2-methylpropanal, another compound of the invention. Finally the compound of formula (I) wherein the dotted line indicates the location of a single bond, n is equal to 0 and R represents a hydrogen atom, namely (4-tert-butyl-1-cyclohexyl)acetaldehyde, is prepared in a one step reaction by lithium aluminum hydride reduction of methyl-4-tert-butyl-1-cyclohexylideneacetate. The different steps of these syntheses will be described in a more detailed manner in the examples hereafter.
The invention will now be described in greater detail in the following examples, wherein the temperatures are indicated in degrees centigrade and the abbreviations have the usual meaning in the art.